I'm facing this same scenario right now -- "Upgrade Requested" disappeared at T-24 and can't check in online for ZRH-LHR-SFO-DEN tomorrow. 3 hours from ZRH so checking in at the airport is not an option. Maybe I'll try to check in on the Swiss site and see if that helps.
Well what do you know -- checked in at the LX website, got my mobile BP and am now magically on the BF upgrade list. Yippee

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